体育锻炼能产生哪些心理学效益？
参考答案：
心境状态有所改善、焦虑和紧张减少、应激和紧张减少。
Only under special circumstances ______ to take those rests.[ ]
A. are freshmen permitted
B. freshmen are permitted
C. permitted are freshmen
D. are permitted freshmen
沉没度是指抽油泵的吸入阀与静液面之间的相对高度。
